Australia have been forced into a late change ahead of their season-opener against Samoa on Sunday that will see Reds winger Rod Davies make his debut as a replacement for the injured James O'Connor.

The 22-year-old Davies is set to make his Test bow after O'Connor was ruled out due to a hamstring injury sustained during a running drill. Davies joins fellow Wallabies debutants - Rebels scrum-half Nick Phipps and Waratahs lock Sitaleki Timani in the side, while the Reds pair of flanker Beau Robinson and hooker James Hanson will gain their first taste of Test rugby if required from the bench.

The full extent of O'Connor's injury is still to be determined, with medical staff to monitor it over the next few days. He has no previous history of hamstring injuries. In the absence of O'Connor, Brumbies fly-half Matt Giteau will assume goal-kicking responsibilities.

Earlier in the week, Waratahs prop Benn Robinson was ruled out for the season after he sustained an injury to the anterior cruciate ligament in his knee. His injury saw Western Force prop Pekahou Cowan added to the squad, taking his place among the run-on reserves.